Portable electrically controlled tapper



June 21, 1938. F. CORDES I PORTABLE ELECTRICALLY CONTROLLED TAPPER FiledOct. 25, 1937 2 Sheets-Sheet 1 A'ITORNE.

June 21, 1938.

F. CORDES PORTABLE ELECTRICALLY CONTROLLED TAPPER Filed Oct. 25, 1937 2Sheets-Sheet 2 INVENTOR.

BY W

' ATTOIIKNEY.

Patented June 21, 1938 UNITED STATES PATENT OFFICE PORTABLE ELECTRIGALLYCONTROLLED TAPPER 9 Claims.

This invention relates to a mechanism for drilling and tapping of thetype wherein the means a? versed and is withdrawn from the work afterthe particular operation has been completed.

More particularly the invention relates to a portable mechanism forclose drilling and tapping wherein the means for operating a tap to forma female screw or for operating a tool for drilling a hole of aparticular depth, has its direction of rotation automatically reversedthereby withdrawing it from the work after the tap or drilling tool hasreached a predetermined depth for which the machine has been previouslyset.

Among the objects of the invention are:-

To safeguard against the breaking of tap forming tools; to save time andlabor by avoiding the necessity of unloading and bringing parts to beoperated on to stationary tapping machines which are cumbersome andunwieldy to handle; to provide an improved combination of drilloperatingand drill handling means which will add to speed and convenience ofoperation, and, in general, to render the construction of such a devicesimpler, more compact and safer to operate.

Other objects, advantages and features of invention will hereinafterappear.

Referring to the accompanying drawings, Figs. 1 and 2combinedlyillustrate what is deemed at present to be a preferredembodiment of the invention, Fig. 1 showing, in perspective, the drivingmechanism for operating the tool shown, in side elevation, in Fig. 2,said tool being shown in combination with the depth gage and associatedswitch box for reversing the direction of rotation of the motor shown inFig. 1.

Fig. 1A is a sectional coupling detail.

Figs. 3, 4 and 5 illustrate plan views of the switch box shown in Fig.2, these views progressively omitting parts from the top downwardly.

Figs. 6 and 7 illustrate side elevations of switch reversing parts shownin Fig. 4..

Fig. 8 is a slightly modified longitudinal midsection taken through aportion of the lower structure shown in Fig. 2.

Fig. 9 is an underside view of the insulated plate shown in the upperpart of the structure of Fig. 2.

Fig. 10 is an enlarged view of the spring part shown in Figs. 4 to 7,and

Fig. 11 is a wiring diagram.

Referring in detail to the drawings, Fig. 1 shows the completetap-operating assembly and comprises essentially a cabinet I supportedupon swivelled wheels 2. By preference and as shown the walls of saidcabinet are substantially rectangular and at one end thereof is mounteda hinged door 3 carrying on its inner side tool shelves 4 and 5. To theend wall of said casing opposite to said door is removably secured apanel 6 by means of bolts, one of which is designated by the numeral 1,projecting thru said panel and the adjacent end wall of the cabinet. 10

Upon aforesaid panel 6 is mounted the operating mechanism shown withinthe casing in Fig.

1 including the motor ID, whose base II is secured to said panel bymeans of bolts l2 which cooperate with the slots I3 to adjustablysupport 15 the motor at various heights.

In the upper part of said casing to said panel are fixedly mounted byany suitable means, as for example hold down bolts l4, brackets 15 whichsupport the bearings IS in which the power delivery shaft 2|] isjournalled. Between the power delivery shaft mounting and motor iscounter shaft 24 fastened adjustably to said panel by means of boltsextending thru slots l8 engaging brackets l9.

The power delivery shaft 20 may be variably speed driven by a V-belt 2|which passes over a multiple-diameter V-grooved pulley 22 fixed to saidshaft, said belt in turn being driven from a multiple diameter pulley 23fixed to the coun ter shaft 24. Said counter shaft is shown driven bythe motor shaft 25 through the medium of motor shaft pulley 26, belt 21and large pulley 28 fixed to said counter shaft.

The belts 2| and 21 may be tightened or loosened by shifting the motor[0 and countershaft 24, aforesaid slots [3 and slots l8 being providedrespectively for hold down bolts l2 of the motor and bolts of thecounter shaft brackets, not shown.

The motor In is of the quick reversing type. It responds to achange incurrent connections by stopping and reversing almost instantaneously.The motor together with the variable speed mechanism, by reason of theirpeculiar mounting are withdrawable bodily as a unit from the casing.

Fig. lA illustrates the manner in which the power delivery shaft 20 maybe disconnected from the remainder of the drive permitting thisdetachability. In said figure is shown a sleeve coupling 29 extendingthru a side wall of the cabinet, said coupling having its inner endjoined by means of a screw 30 to the free end of the shaft 28 whichprojects thru the bearing [6 nearest said side wall.

Continuing the description of the coupling means, the power deliveryshaft 28 has detachably connected to it the flexible shaft structure 40the continuing terminal portion of which is shown in Fig. 2 projectingoutside the casing thru an aperture 36 provided therefor, screw 31 beingprovided for attaching the inner terminal portion of the shaft 38 which,in turn, is fastened to the cable 39 that operates the tapping tool 4|.

Referring more particularly to Fig. 2, the tapping tool 4| is shownsecured to the flexible driving shaft 48 by means of a conventionaldrill chuck 42, the adjacent part of the flexible shaft being surroundedby a bushing 43 with which is combined the body portion 44 of the depthgauge, current connection, direction changing apparatus indicatedgenerally by the reference numeral 45.

The tap depth gauge includes a bar 46 which is longitudinally adjustablefrom a retracted, nonoperative position to an extended position whereinit maintains a gauge rod 41 carried by it in a position automatically togauge the depth to which the taps will be operated to form the thread.

The gauge rod 41 has a slidable fit within a slot 46a within said bar46, the amount of its extrusion therefrom being fixedly maintained bythe set screw 48. Said gauge bar has an offset terminal portion 49located close to the tool 4| for engagement with the work being operatedupon, the distance from the end of the terminal 49 to the end of the taprepresenting approximately the distance the tap will go into the workbefore it is reversed by an automatic change in current connection andcaused to back out.

The mechanism whereby this reversal is efiected will now be describedwith particular reference to Figs. 2 to 11.

Fig. 2 discloses the arrangement of parts comprising the depth gauge,current connection direction changing apparatus in superposed relation;that is to say, bushing 43 supports part 44 comprising the body portion,part 44 which houses the current changing apparatus in turn supportscover plate 50, and part 50 in turn supports the uppermost partcomprising a bakelite insulator which is adapted to cap the terminals ofthe conductors thru which a change of current is effected.

Part 5| is cavitated on its under side as shown by the numeral 53 inFig. 9. Said part is secured to its adjacent part 56 by means of screw54 tapped into hole 55 shown in Fig. 3 and by means of screw 56extending thru hole 51 in part 59 and screwed into tapped hole 58 shownin part 44 in Figs. 4 and 5.

Part 58, in addition to its fastening to part 44 by means of screw 56,is also fastened to the latter part by means of screw 60 screwed intotapped hole 6| shown in Figs. 4 and 5.

Fig. 3 shows part 50 with part 5| removed and Fig. 4 shows part 44 withpart 58 removed. Fig. 5 shows part 44 stripped of its movable parts, i.e., springs 62 and 63 and switch actuating bars 46 and 64, the latterparts also being separately shown in Figs. 6 and 7. Part 44 is securedto the bushing 43 by means of screws 65 and 66.

When the machine is tapping, the parts have the relative positions shownin Fig. 4. This relation is also shown in Fig. 3. This relative relationis maintained by means of a spring 62 abutting the inner end of bar 46anda leaf spring 68 fastened to the body portion 44 by means of a screw69 extending thru a slot 18 in said spring, said spring 68 havingtapered edges H and I2 engaging notches 13 and 14 in bars 46 and 64respectively and said bar 46 being provided with a rounded shoulderbetween notches l3 and 76 to permit movement of leaf spring 68 from theformer notch to the latter. This position is maintained until the gaugebar is manually actuated by means of the trigger 15 depressing saidspring to release it from notch 13 and cause it to occupy notch 16, orthe spring is depressed by virtue of the contact of the bar 49 with thework effecting the same movement. Either means will cause the spring 68to become depressed whence a change in current connection is effected.

The spring 68 is shown in Fig. on an enlarged scale with its reverselytapered edges H and 12 which make for better operation of the spring.This spring when assembled with its associated parts as shown in Fig. 4,is placed slight- 1y under a bending strain at its bend.

Now when the bar 41 strikes the work it is forced to the left causingleaf spring 68 (Fig. '7) to leave notch 73 and enter notch 16. Thisoperation causes the edge 12 of spring 68 to move down out of notch 14in Fig. 6. The spring 63 of Fig. 4 is now free to force bar 64 to theleft until the edge 12 of spring 68 in Fig. 6 has contacted stop 11.Lead 8| of Fig. 3 now has contacted lead 88 at contact point 19 (I9 is aflat springy piece of copper fastened under nut 18). This change incurrent connection reverses the direction of rotation of the motor andbacks the tap out.

When the motor is to be started in the forward direction again, theoperator pushes with his thumb on the left end of bar 64 (Fig. 3) andreloads the mechanism to the position shown by Figs. 3 and 4.

Bar 46 never stays back to the left with edge ll of spring 68 in notchI6 (Fig. 7) after it is released by the work, because spring 62 (Fig, 4)forces bar 46 to the right whenever part 49 is not contacting the work.

Numerals 88, 8| and 82 indicate three leads from the motor in aninsulating tube 84 which rests in a groove 85 of Fig. 5. Said leads comeup thru insulating cover 50 of Fig. 3 as shown. Yieldable part 86 ofFig. 3 comprises a spring fastened under nut 8'! and serves as contactfor nut 81a in the position shown. Spring 86 gives the play necessary toinsure bar 64 moving far enough to the right so that the edge 12 ofspring 68, Fig. 6, can enter notch 11.

As shown by the wiring diagram in Fig. 11 there are three leads 80, 8|and 82 from the motor. If 8| contacts 80 at points 81a and l8 (19) themotor turns in a counter-clockwise direction; if 8| contacts 82 atpoints 81a and 81 as shown, the motor turns in the clockwise direction.These three leads are shown in Fig. 3, 8| being fastened to bar 64 whichis slidable in a metal box described as body portion 44 in Fig. 4.Numerals 95, 96, 91, 98and 99 in Fig. 11 are shown as being plugcontacts in Fig. 1. I00 indicates a switch which may be placed in thepower line source in close proximity to the operator when he is at aremote distance from the casing.

It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents which fall within the scope of the subject matterclaimed.

What I claim is:

1. In a portable electrically operable machine for tapping holes ofvarious drilled depth and at the completion of the tapping operationhaving the direction of movement of the tap reversed whereby it iswithdrawn out of the hole, a portable cabinet, a detachable panelfastened to a wall of said cabinet, driving mechanism fastened to saidpanel and withdrawable therewith from said cabinet, a tapping tool,flexible driving means connecting said tool and said driving mechanism,means toactuate said tool thru the medium of said flexible means andsaid driving mechanism, and means mounted adjacent said tool forautomatically reversing the direction of rotation of said drivingmechanism upon completion of a tapping operation.

2. In a portable electrically operable machine for tapping holes ofvarious drilled depth and at the completion of the tapping operationhaving the direction of movement of the tap reversed whereby it iswithdrawn out of the hole, a portable cabinet, a detachable panelfastened to a wall of said cabinet, a quickly reversible motor fastenedto said panel, a tap, variable speed driving mechanism mounted upon saidpanel interconnecting said motor and tap, flexible driving meansconnecting said tap and said variable speed driving mechanism, a depthgauge mounted adjacent to said tap for regulating the depth of holebeing tapped, and means associated with said depth gauge automaticallyto reverse the rotation of said motor when a predetermined depth oftapping is reached.

3. A portable cabinet, a detachable panel fastened to an inside wall ofsaid cabinet, variable speed. driving mechanism mounted upon said panel,a quick reversing electric motor also mounted upon said panel, drivingmeans operatively connecting said motor and said variable speedmechanism, said driving means, variable speed mechanism and motor beingbodily withdrawable as a unit from said cabinet, a tool, flexibledriving means connected to said variable speed mechanism for operatingremotely said tool, means fastened to said flexible driving meansadjacent said tool for automatically reversing the direction of rotationof said motor upon the completion of a working operation of said tool,and

manually operable means fastened to said automatically reversing meansto at will also reverse the direction of rotation of said motor.

4. A portable cabinet, a detachable panel fastened to an inside wall ofsaid cabinet, variable speed driving mechanism mounted upon said panel,a reversible electric motor also mounted upon said panel, driving meansoperatively connecting said motor and said variable speed mechanism,said driving means, variable speed mechanism and motor being bodilywithdrawable as a unit from said cabinet, a tool, flexible driving meansconnected to said variable speed mechanism for operating remotely saidtool, a bushing fastening said tool to said flexible driving means, agauge mounted upon said bushing in a predetermined relation with saidtool, said gauge being adjustable for governing the operation of saidtool upon the work being operated upon, and said gauge upon thecompletion of a working operation automatically reversing the directionof rotation of said motor for withdrawing said tool from the work beingoperated upon, and electrical connections effecting a change in currentof said motor actuated by the movement of said gauge.

5. A cabinet including a detachable panel, a power delivery shaftmounted on said panel, motor means including a variable speed drivemounted on said panel to actuate said shaft, 2. tool, flexible drivingmechanism operatively connecting said tool and said power deliveryshaft, apparatus including current connections mounted on said flexibledriving means adjacent said tool, and means mounted in juxtaposition tosaid tool and operatively related to said apparatus and currentconnections, automatically to effect a change of said currentconnections.

6. A cabinet, a power delivery shaft mounted in said cabinet, motormeans including a variable speed drive mounted in said cabinet foroperating said shaft, a tool, flexible driving mechanism relating saidtool and said shaft for operating said tool remotely from said cabinet,current reversing mechanism mounted on said flexible mechanism adjacentsaid tool, means mounted on said flexible mechanism in juxtaposition tosaid tool to gauge the operation of work performed by said tool,conductors connecting said current reversing mechanism and said motor,and means associated with said gauge means to actuate said currentreversing mechanism automatically to cause said motor to rotate in theopposite direction.

7. A portable cabinet, a detachable panel fastened to an inside wall ofsaid cabinet, variable speed driving mechanism mounted upon said panel,an electric motor also mounted upon said panel, driving meansoperatively connecting'said motor and variable speed mechanism, saiddriving means, variable speed mechanism and motor being bodilywithdrawable as a unit from said cabinet, a tool, flexible driving meansconnected to said variable speed mechanism for operating remotely saidtool, and means fastened to said flexible driving means adjacent saidtool for automatically reversing the direction of rotation of said motorupon the completion of a working operation of said tool.

8. A portable cabinet, a detachable panel fastened to an inside wall ofsaid cabinet, variable speed driving mechanism mounted upon said panel,an electric motor also mounted upon said panel, driving meansoperatively connecting said motor and said variable speed mechanism,said driving means, variable speed mechanism and motor being bodilywithdrawable as a unit from said cabinet, a tool, flexible driving meansconnected to said variable speed mechanism for operating remotely saidtool, a bushing fastening said tool to said flexible driving means, anda gauge mounted upon said bushing in a predetermined relation with saidtool, said gauge being adjustable for governing the operation of saidtool upon the work being operated upon.

9. A cabinet, a power delivery shaft mounted in said cabinet, motormeans mounted in said cabinet operatively related to said shaft, a tool,driving mechanism relating said tool and said shaft for operating saidtool remotely from said cabinet, current reversing mechanism mounted onsaid driving mechanism adjacent said tool, means mounted on said drivingmechanism in juxtaposition to said tool to gauge the operation of workperformed by said tool, conductors connecting said current reversingmechanism and said motor, and means associated with said gauge means toactuate said current reversing mechanism automatically to cause saidmotor to rotate in the opposite direction.

FERDINAND CORDES.

